Automatic electric-circuit breaker



l+, E. WADSWORTH AND W. B. ENSIGN.

AUTOMATIC ELECTRIC CIRCUIT BREAKER.

APPLICATION FILED FEB. I6. 1920.

H. E. WADSWORTH AND W. B. ENSIGN.

AUTOMATIC ELECTRIC CIRCUIT BREAKER.

. APPLICATION FILED FEB. I6. I920. 1,368,003.

Patented Feb. 8,1921.

2 SHEETS-SIIEET 2.

uurrso STATES PATENT OFFICE.

HARRY E. WADSWORTH, OF NEW YORK, AND WILLIAM B. ENSIGN, OF WHITE PLAINS,

NEW YORK.

AUTOMATIC ELECTRIC-CIRCUIT BREAKER.

Specification of Letters ratent.

Patented Feb. 8, 1921.

To all whom it may concern:

Be it known that we, HARRY E. WADS- WORTH, a citizen of the UnitedStates, and a resident of the borough and county of Bronx, city andState of New York, and WILLIAM B. ENsIGN, a citizen of the UnitedStates, and a resident of White Plains, count of Westchester, and Stateof New York, ave invented certain new and useful Improvements inAutomatic Electric-Circuit Breakers, of which the following is aspecification.

Our improvements relate to means for automatically breaking or openingan electric circuit when a predetermined excess of current occurs,substantially as set forth in our concurrent application Serial No.314,- 552, filed July 31, 1919, the object, as in that case, beingprimarily to dispense with cut-out fuses by providing an equivalenttherefor to be positioned in like manner between the usual spring clipterminals; to effectually protect the operative parts and preventtampering therewith, etc.,0ur invention in the present case consistingin the construction, combination and arrangement of parts hereindescribed and claimed specifically, whereby these desired results areattained; and distinctive features in the present case being the duplextrip break and re-set mechanism, and the employment of a solenoid(hammer) plunger to effect an instantaneous break of circuit wheneverthe strength of the electric current exceeds a rescribed degree ofintensity, all as hereinafter fully set forth.

In the accompanying drawings,

Figure 1, is a front elevation of our improved circuit breaker;

Fig. 2, is an end elevation thereof;

Fig. 3, is a front view of our circuit breaker as mounted between knifeblade circuit terminals;

Fig. 6, is a like view unto Fig. 4, illustratingwthe re-set of theoperative parts;

ig. 7, is a section taken upon plane of line 7--7, Fig. 4;

Fig. 8, is a section taken upon plane of line 8-8, Fig 4;

Fig. 9, is a detail view, upon a larger scale, showing the pivotalconnection between the upper ends of the blade contact levers, ac-

tuating springs, etc.;

F g 9 is an enlarged detail of Fig. 9;

Fig. 10, 1s a sectional detail taken upon plane of line 10l0, Fig. 9;

Fig. 11, 1s a detail view of one of the latch lever springs;

Flg. 12, 1s a diagrammatic representation of the electric contactsincidental to our device.

Fig. 13, is a transverse section taken upon plane of line 13-13, Fig. 4.The casing of insulating material is made in two parts U, 0, eachforming one half of the basic structure, and each being substantially areversed duplication of the other. The extremities of each halfaresemi-circular, so that when the halves are fitted to gethercylindrical ends are formed over which the cylindrical metallic ferrulecaps F, F, fit, binding the two said non-conductive parts (J, U, of thehousing together. These parts U, C, are further secured together by therigidly mounted cross rods 0, c, and further, if desired, by screws orbolts for which holes 0, 0, may be provided as indicated in Figs. 4, 5and 6.

Each ferrule cap F, F, is slidable within certain prescribed limits, onits end of the casing for the purpose of re-setting the other operativeparts, as hereinafter set forth, after a break in the electriccircuit,-stops 1', r, being provided to limit the outward movement ofsaid ferrules. These ferrule caps may be adapted, when in closed normalposition on the cylindrical ends of the casing, for insertion betweeneither spring terminal clips as indicated in Fig. 2, or for engagementwith knife blade circuit terminals, as in Fig. 3, in which latter viewthe device is shown as adapted to either form of terminal connection.

The medial portions of the halves C, C, of the non-conductive casing areformed with coincidental lateral extensions 0*, and are recessed toafford operative space-for the movable parts of the switch controlmechanism.

S, is a solenoid coil fixedly mounted upon and between the lateralextensions (3*, C, of the casing C, C, the opposite ends .9, s, of thecoil 8, of which are connected with fixed contact plates 8*, e embeddedrespectively in the cylindrical extremities of the casing as shown moreparticularly in Figs. 7 and 8. fly, are contact plates affixed to theferrules F, respectively, and movable therewith, and in parallelrelation to the aforesaid fixed contact plates 8*, 8*. l0, 7:, are knifeblade switch plates movable be tween, and adapted to contact with saidfixed contact plates s, 8*, and said movable contact plates 7', f. Oneof the knife blade switch plates, Ir, is pivotally connected with thetoggle lever 2 and the other A1, with the toggle lever 6, both of whichtoggle levers t, t, are pivotally supported on the fulcrum bar Z),rigidly attached to, and positioned between, the halves C, C, of thecasing, as shown more particularly in Fig. 7.

Z, Z, are latch levers fulcrumed on the cross rods 0, c, and controlledby spring: 0*, 0*, which tend constantly to hold their adjacent innerends in contactual engagement with studs 3), p, protuberant fromopposite sides of a trip-plunger P. The latter straddles the fulcrum barZ), being formed with a slot 79', for this purpose. Normally, when theoperative parts are in circuit-closed relationship as in Figs. 4 and 6,one end wall of the slot 3), rests against the fulcrum bar Z), (as shownin Fig. 9, Fig. 9) which thus acts as a stop to the thrust of the latchlever springs 0*, 0",said slot p, being of a length to allow the tripplunger P, longitudinal movement in the opposite direction sufficient tocause it to rock the latch levers Z, Z, against the resistance of theirsprings 0*, c", to release the outer ends of said latch levers Z, Z,from the shoulders 6 25*, on the free ends of the toggle levers t, t, asshown in Fig. 5, when said trip-plunger P, is actuated by the solenoidhammer core h, as happens whenever the electric current passing throughthe solenoid coil 8, exceeds a prescribed degree of intensity. Thistripping operation is illustrated in Fig. 5, which also shows the togglelevers Z, Z, as collapsed inward centrally toward each other under thepressure of the springs t t affixed to the cross bar Z), and havingtheir free ends bearing upon said toggle levers t, t, as shown moreparticularly in Figs. 9 and 10, of the drawings. This collapse of thetoggle levers Z, Z, of course withdraws the knife blade switch platesZ0, is, from contactual engagement with both the fixed contact plates8*, 8*, and the movable contact plates 7, f, thereby opening theelectric circuit, whereupon the solenoid hainmer core h, is immediatelydemagnetized and returned by its retractile spring h, to its normalposition, as in Figs. 4 and 6.

To reinsert the knife blade switch plates 7c, is, between the fixedcontact plates 8X, 8*, and the movable contact plates 7, f, and

pea

thus again close the electric circuit the ferrules F, F, after removalfrom the main circuit terminals are slid outward on the cylindrical endsof the casing as shown in Fig. (i, causing the stop shoulders r, on theinner ends of the slides r, '1", (which are attached to said ferrules)to return the toggle levers If, t, to normal extended position, when thelatch levers Z, Z, automatically re-lock said toggle lovers 1%, t, withtheir knife blade contact plates 8*, s, again in closed contactualrelationship with the aforesaid fixed and movable contact plates, asshown particularly in Fig. 8.

The retractile spring 7L, interposed between the solenoid hammer core7L, and the end of the trip plunger P, while sufficient in strength toeffect the return of the hammer core h, to normal position whendemagnetized by the opening of the electric circuit, and to retain ittherein so long as the current passing through the solenoid coil 8, isnormal, is insuflicient in resistive strength to prevent the hammer-corefrom impinging suddenly and forcefully against the end of the tripplunger P, whenever an abnormal intensity of current seeks to passthrough said solenoid coil, so that the break of circuit is practicallyinstantaneous. As a re sult the electric circuit is opened with aminimum of sparking and heat generation incidental to contactseverance,the intensity thereof being sub-divided between the two knifeblade switch plates Zr, 7;, and their respective movable and fixedcontact plates. h is a set screw for regulating the available thrust ofthe solenoid hammer core It, as related to the trip plunger P.

As in.tl1e case of our cut-out slide circuit breaker described in saidconcurrent application Serial No. 314,552, it will be seen that in ourpresent device the switch latch may be reset, when the device is removedfrom between the terminal clips, without opening the casing, and by thesimple expedient of reciprocating portions thereof.

Furthermore all the operative parts of the circuit breaker are inclosed,isolated, and protected from contact with extraneous objects: and theycannot be tampered with or improperly manipulated while the incasementis intact. The device is an effectual substitute for. the blow-out fuse,with the great advantage that it can be reset and used indefinitely; andthe" act of re-setting simply involves its removal from between thecircuit terminal clips and the manipulation of the ferrule caps F, F,after which it is ready for replacement in operative position.

By the term electric circuit terminal spring clips as used herein wemean either the knife blade terminals shown in Fig. 3, or the claspsshown in Fig. 2.

\Vhat we claim as our invention and desire to secure by Letters Patentis,

1. An automatic electric circuit breaker of the character designated,comprising a casing of insulating material, metallic ferrule caps formedexternally for contactual engagement with main electric circuit terminalspring clips, fixed contact plates, one in each cylindrical extremity ofthe casing, a solenoid the coil ends of which are connected with saidfixed contact plates, movable contact plates, one attached to eachferrule in parallelism with the aforesaid fixed contact plates, knifeblade switch plates movable between and adapted to contact with saidfixed and said movable ferrule contact plates, toggle levers pivotallyconnected with said knife blade switch plates and with a trip plunger,said trip plunger, spring latch levers contacting with said trip plungerand adapted to engage with shoulders on said toggle levers, and asolenoid hammer-core adapted to actuate said trip plunger, for thepurpose described.

2. An automatic electric circuit breaker of the character designated,comprising a casing of insulating material, metallic ferrule caps formedexternally for contactual engagement with main electric circuit terminalspring clips, fixed contact plates, one in each cylindrical extremity ofthe casing, a solenoid the coil ends of which are connected with saidfixed contact plates, movable contact plates, one attached to eachferrule in parallelism with the aforesaid fixed contact plates, knifeblade switch plates movable between and adapted to contact with saidfixed and said movable ferrule contact plates, toggle levers pivotallyconnected with said knife blade switch plates and with a trip ed toactuate said trip plunger, said trip plunger, spring latch leverscontacting with said trip plunger and adapted to engage with shoulderson said toggle levers, a solenoid hammer core adapted to actuate saidtrip plunger, and a re tractile spring interposed between said tripplunger and said solenoid hammer core, for the purpose described.

3. An automatic electric circuit breaker of the character designated,comprising a casing of insulating material, metallic ferrule caps formedexternally for contactual engagement with main electric circuit terminalspring clips, fixed contact plates, one in each cylindrical extremity ofthe casing, a solenoid the coil ends of which are connected with saidfixed contact plates, movable contact plates, one attached to eachferrule in parallelism with the aforesaid fixed contact plates, knifeblade switch plates movable between and adapted to contact with saidfixed and said movable ferrule contact plates, toggle levers pivotallyconnected with said knife blade switch plates and with a trip plunger,said trip plunger spring latch levers contacting with said trip plungerand adapted to engage with shoulders on said toggle levers, a solenoidhammer core adaptplunger, a retractile spring interposed between saidtrip plunger and said solenoid hammer core, and means for adjusting theavailable thrust of said solenoid hammer core as related to the saidtrip plunger, for the purpose described.

HARRY E. WADSWORTH. WILLIAM B. ENSIGN.

Witnesses:

Gno. WM. MIATT, L. H. BRADLEY.

